Neonatal jaundice is one of the most common diagnoses in the neonatal period; it is estimated to occur in 60% of term newborns in the first week of life. In rare instances, the Total Serum Bilirubin (TSB) reaches levels that can cause kernicterus, a condition characterized by bilirubin staining of neurons and neuronal necrosis involving primarily the basal ganglia of the brain and manifested in athetoid cerebral palsy, hearing loss, dental dysplasia, and paralysis of upward gaze, We conducted a prospective study to detect the serum rebound bilirubin among term And preterm newborns diagnosed with neonatal hyperbilirubinaemia who were admitted to the NICU of Al-Galaa Teaching Hospital and NICU of Pediatrics department of Banha University Hospital, requiring double surface, and intensive phototherapy treatment. This was a prospective study to detect the serum rebound bilirubin among100 term & preterm newborns diagnosed with neonatal hyperbilirubinemia who were admitted to the NICU of Banha University Hospital and AL-Galaa Teaching hospital, requiring double intensive phototherapy treatment. This study is from April 2015 to December 2018, Total Serum Bilirubin 4 -48 hours after discontinuation of phototherapy, significant bilirubin rebound is considered with increased by 2.04 mg/dL after stopping phototherapy and needing readmission. There were no significant differences between neonates with rebound hyperbilirubinemia and those without as regard birth weight (P value = 0.745), There was no significant difference between discharge level (4-48hour post intensive photo) (10.0) and after intensive phototherapy level (9.72), we concluded that It is not necessary to keep infants in the hospital to check for rebound because of rare instance of serum billirubin rebound but clinical follow-up 24 to 48 hours later is important furthermore follow up for a risk factor group is a must and keep infant in the hospital should be taken into consideration.